--- title: Threat Report 4/27/26 description: Explore the latest high-risk vulnerabilities impacting Microsoft, Chrome, Mozilla, and Adobe products, along with new federal discussions on AI-driven security tools like Mythos. --- [HTG Threat Report ](https://www.harbortg.com/htg-threat-report) # [Threat Report 4/27/26](https://www.harbortg.com/htg-threat-report/threat-report-4/27/26) Written by [Evan Kennedy](https://www.harbortg.com/htg-threat-report/author/evan-kennedy) | Apr 27, 2026 3:56:33 PM ### Critical Microsoft Vulnerabilities Demand Immediate Action   Serious security flaws have been identified across multiple Microsoft products, with the most critical enabling remote code execution under the logged-in user’s account. In practical terms, attackers could install malicious programs, manipulate or delete data, and even create accounts with full administrative privileges. Systems running with elevated permissions face significantly higher risk. **Impacted Platforms:** - Widely used Microsoft products including Windows, Office, and Edge **Risk Level:** - Large & Medium Businesses: **High** - Small Businesses: **Medium** **What You Should Do Now:** - Update all Microsoft systems to the latest versions immediately - Apply the Principle of Least Privilege to limit unnecessary access rights **References:** - [https://msrc.microsoft.com/update-guide/en-us](https://msrc.microsoft.com/update-guide/en-us) - [https://msrc.microsoft.com/update-guide/releaseNote/2026-Apr](https://msrc.microsoft.com/update-guide/releaseNote/2026-Apr) ### Google Chrome Vulnerabilities Open Door to Code Execution   Newly discovered vulnerabilities in Google Chrome could allow attackers to execute arbitrary code on affected systems. If exploited, this could lead to full system compromise depending on user privileges. **Impacted Versions:** - Chrome prior to 147.0.7727.101/102 (Windows & Mac) - Chrome prior to 147.0.7727.101 (Linux) **Risk Level:** - Large & Medium Businesses: **High** - Small Businesses: **Medium** **Recommended Actions:** - Update Chrome across all devices without delay - Restrict elevated permissions using least privilege practice **References:** - [https://chromereleases.googleblog.com/2026/04/stable-channel-update-for-desktop_15.html](https://chromereleases.googleblog.com/2026/04/stable-channel-update-for-desktop_15.html)** ** -     ### Mozilla Products Affected by Critical Code Execution Flaws   Multiple high-impact vulnerabilities in Firefox and Thunderbird could allow attackers to execute code within a user’s session, potentially leading to full compromise of affected systems. **Impacted Versions Include:** - Firefox < 150 - Firefox ESR < 140.10 / 115.35 - Thunderbird < 150 - Thunderbird ESR < 140.10 **Risk Level:** - Large & Medium Businesses: **High** - Small Businesses: **Medium** **Mitigation Steps:** - Upgrade all Mozilla applications to the latest releases - Enforce strict privilege controls across user accounts **References:** - [https://www.mozilla.org/en-US/security/advisories/](https://www.mozilla.org/en-US/security/advisories/) - [https://www.mozilla.org/en-US/security/advisories/mfsa2026-30/](https://www.mozilla.org/en-US/security/advisories/mfsa2026-30/) - [https://www.mozilla.org/en-US/security/advisories/mfsa2026-31/](https://www.mozilla.org/en-US/security/advisories/mfsa2026-31/) - [https://www.mozilla.org/en-US/security/advisories/mfsa2026-32/](https://www.mozilla.org/en-US/security/advisories/mfsa2026-32/) ### Adobe Product Vulnerabilities Put Systems at Risk   A wide range of Adobe products are affected by vulnerabilities that could allow arbitrary code execution. Exploitation could give attackers control within the user’s environment. **Impacted Software Includes:** - Acrobat, Reader, Photoshop, Illustrator, InDesign, InCopy - Adobe Connect, ColdFusion, FrameMaker, Bridge, and more **Risk Level:** - All Business Sizes: **Medium** **Immediate Actions:** - Update all Adobe software to current versions - Limit administrative privileges wherever possible -   ### White House Officials Meet With Anthropic CEO Over Mythos Concerns   CNBC [reports](https://www.cnbc.com/2026/04/17/anthropic-dario-amodei-trump-mythos.html?utm_campaign=28306244-N2K%20CyberWire%20%7C%20CyberWire%20Daily%20Briefing&utm_medium=email&_hsenc=p2ANqtz-_XexAl6ArvjVJT_ShxYlLrXLb8GMCzidH8MsWECgEJ_XKcO3iEioxodzZvGVBr52uRV557BqAGSp5Cf1qmrsuL9wyCwg&_hsmi=414685178&utm_content=414685178&utm_source=hs_email) that White House Chief of Staff Susie Wiles, Treasury Secretary Scott Bessent, and other senior officials met with Anthropic CEO Dario Amodei on Friday to discuss Mythos, an Anthropic model designed to find software security flaws. The White House and Anthropic both described the meeting as "productive," and the White House added in a statement, "We discussed opportunities for collaboration, as well as shared approaches and protocols to address the challenges associated with scaling this technology. The conversation also explored the balance between advancing innovation and ensuring safety." CNBC notes that the meeting is a sign of thawing relations between the White House and Anthropic, although President Trump later told reporters that he had "no idea" Amodei was present. [View full post](https://www.harbortg.com/htg-threat-report/threat-report-4/27/26) ```json { "@context" : "http://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "Evan Kennedy" }, "dateModified" : "2026-04-27T17:35:08.892Z", "datePublished" : "2026-04-27T15:56:33Z", "headline" : "Threat Report 4/27/26", "image" : { "@type" : "ImageObject", "height" : 628, "url" : "https://5580335.fs1.hubspotusercontent-na1.net/hubfs/5580335/ThreatReport2025%20%283%29.png", "width" : 1200 }, "mainEntityOfPage" : "https://www.harbortg.com/htg-threat-report/threat-report-4/27/26", "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "height" : 60, "url" : "/hs/hsstatic/content_shared_assets/static-1.4092/img/default-amp-logo.png", "width" : 60 }, "name" : "HTG Threat Report" } } ```